Biochemistry is the study of life on the microscopic level. It ranges from why atoms form molecules to what different cells in the body do. This page will focus on the molecule deoxyribonucleic acid, otherwise known as DNA.

      DNA is the information molecule of life. It stores all the genetic information that tells what a living organism is. For example, it is a person's DNA that determines what color their eyes are, what color their hair is, and, for that matter, that they are a human being. Our DNA basically controls everything about us.

      There is DNA in almost every cell of our body. It is stored in the nucleus, a pocket in the center of the cell. For most of the time, it is wound up very tightly. It only unwinds when it is used to create proteins or when the cell divides.

      DNA is a huge molecule. It is composed of thousands upon thousands of smaller molecules. If one were to look at a very magnified section of DNA, it would look like a double helix, or two interwound spirals (see below). These spirals are composed of an alternating chain of deoxyribose, a sugar molecule, and phosphate. This double helix is very, very long. A complete strand of DNA from a human is about five inches long if it is stretched out straight. This is incredibly long for a single molecule. Between each deoxyribose molecule on the DNA, there are two nucleotides. There are four different kinds of nucleotides: adenine, cytosine, guanine, and thymine. The molecules between the deoxyribose molecules are a pair of nucleotides. Pairs can consist of either adenine and thymine, cytosine and guanine, guanine and cytosine, or thymine and adenine.

      The information on the DNA is decoded during a process called transcription and translation. During these processes, the order of the nucleotides tells the cell to produce certain proteins and how to produce them. These proteins regulate everything in our body. This is a very brief explanation, but a detailed description would require too much time.


Here is a three dimensional model of DNA. Hold the mouse down on the picture and move it to see the DNA from different angles.

= Deoxyribose = Phosphate
= Adenine = Cytosine
= Guanine = Thymine

Now you know the basics about DNA. Click here to learn about Recombinant DNA.

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